In turbomachinery and in many other mechanical applications, it is often required that fluid in a high pressure cavity be prevented from flowing into a lower pressure cavity. For instance, in gas turbine systems, a compressed working fluid (e.g., pressurized air from the compressor) may be supplied to many high pressure areas of the gas turbine to provide cooling. As an example, the working fluid may be supplied to high pressure cavities defined between adjacent rotor disks of the gas turbine to cool portions of the disks. However, due to gaps between the rotor disks, a significant portion of the working fluid may often leak to lower pressure cavities at or adjacent to the disks, thereby leading to decreased performance and/or efficiency of the gas turbine.
Various strategies are known in the art to prevent system losses due to fluid leakage between adjacent components. For example, piston ring seals and other continuous ring seals have been utilized in the past to seal the gaps between adjacent rotating components, such as adjacent rotor disks of a gas turbine. However, due to their fixed, annular geometry, these seals are often difficult to install between such components. Moreover, in gas turbine applications, it is often desirable to have a small fraction of the pressurized fluid contained within the high pressure cavities of the turbine to flow into lower pressure cavities to prevent uneven thermal growth of the components disposed adjacent to such cavities. However, by forming an unbroken, continuous annular shape, piston ring seals and other continuous ring seats may completely seal off the gap defined between adjacent rotating components, thereby preventing any of the pressurized fluid from passing into a lower pressure cavity disposed adjacent to the rotating components.
Accordingly, a seal that substantially seals a gap defined between adjacent rotating components and that also allows for a small fraction of pressurized fluid to pass through the seal would be welcomed in the technology.